Aluminum base alloy die casting wheel

ABSTRACT

An aluminum base alloy and an automobile wheel diecast therefrom, the alloy consisting essentially of aluminum and by weight percentage of the total composition, magnesium 0.25 to 0.6%, copper 0.25 to 0.6%, iron 0.5 to 1.5%, silicon 11 to 13.5%, chromium 0.25 to 0.4%, a maximum of 3% zinc, a maximum of 0.5% manganese and a maximum of 0.2% of each of titanium, nickel, tin and lead.

ihtited States Patent I 11 1 Lindberg et a1.

1111 3,856,360 Dec. 24, 1974 ALUMINUM BASE ALLOY DIE CASTING WHEEL [75]Inventors: Richard S. Lindberg, Homewood;

G. Leslie Armstrong, Crete, both of [7'3] Assignee: U.S. Reduction C0.,East Chicago,

Ind.

[22] Filed: Mar. 1, 1973 21 Appl. No.: 337,002

Related US. Application Data [62] Division of Ser. No. 85,372, Oct.30,1970, Pat. No.

52 us. 01 301/65, 75/142 51 Int. l B 60b l/081,C22c 21/02 158 Field ofSearch 75/140, 141,142, 14s, 1

[56] References Cited UNITED STATES PATENTS Blackmun 75/148 3,128,176'4/1964 Martin ..75/148 3,199,979v 8/1965 Martin 75/142 Primary ExaminerR. Dean Attorney, Agent. or Firm-Dressler, Goldsmith. Clement & Gordon,Ltd.

57 ABSTRACT An aluminum base alloy and an automobile wheel diecasttherefrom, the alloy Consisting essentially of aluminum and by weightpercentage of the total composition, magnesium 0.25 to 0.6%, copper 0.25to 0.6%,

iron 0.5 to 1.5%, silicon 11 to 13.5%, chromium 0.25

' to 0.4%, a maximum of 3% zinc, a maximum of 0.5%

manganese and a maximum of 0.2% of each of titanium, nickel, tin andlead.

2 Claims, 2 Drawing Figures 1 ALUMINUM BASE ALLOY DIE CASTING WHEEL.

This is a division of application Ser. No. 85,372, filed Oct. 30, l970,now US. Pat. No. 3,726,672. 5

This inventionrela tes to an aluminum base alloy having high strength,excellent die-casting characteristics, excellent machinabilityv andsuperior mechanical properties. It is especially useful for the diecasting of automobile wheels, although its application is not solimited.

With the advent ofa keen interest in the use of lightweight aluminumbase alloys for articles which must stand the abuse and stressesheretofore reserved for ferrous metals and alloys, it became importantto develop improved aluminum base alloys for such products. However, tobe maximally useful for automobile wheels and other such products,aluminum base alloys had to be die-castable, corrosion'resistant,readily machinable and of a higher strength than those aluminum basealloys previously available and at a-lower cost than other availablealloys having comparable properties.

Although aluminum base die-cast alloys have been on the market for manyyears where lightweight, accuratedimensioning and the like wasimportant, generally those alloys were not suitable for use inapplications where substantial abuse and high stresses were-encountered.

- The only alloy which met with limited successin, and

which has properties generally suitable for high stress applications,such as in die-cast automobile wheels, is one known to the trade as 364alloy. This is made generally in accordance with Blackmun US. Pat. No.2,823,995. Although that alloy improved upon prior art alloys in certainrespects, the properties of that alloy were not as good aswas'desirable. Furthermore, the cost of that alloy was too high 'forgeneral use. Consequently, insofar as aluminum base alloy die castautomobile wheels were concerned, that alloy was used only for highcostspecialty wheels.

in accordance with this invention an aluminum base die-casting alloyhaving substantially improved mechanical properties is provided. ltscost is substantially lower than the cost of the 364 alloy previouslyused for similar purposes, and indeed scrap aluminum and other secondaryaluminum available for secondary reformulation, rather than primaryaluminum, may be used to compound the alloy of this invention. As such,the alloy ofthis invention provides the commercial potential, for

by weight'of the final alloy, 0.25 to 0.6% magnesium; 0.25 to 06%copper; 0.5 to l.5% iron; ll to l3.5% silicon; and 0.25 to 0.4%chromium. The high silicon content and the copper content substantiallycontribute, we believe, in combination with the other ingredients to thesuperior physical properties of this alloy.

The composition 'of this invention which maximizes the characteristicsand properties of die-cast products. such as automobile wheels, whileminimizing the costs attendant the manufacture anduse of the alloycomposition, consists essentially of aluminum. and by weight of thefinal alloy, 0.25 to 0.6% magnesium. 0.25 to 0.6% copper, 0.5 to l.5%iron, ll to. 13.5% silicon, 0.25 to 0.4% chromium, a maximum of 3% zinc,a maximum of 0.5% manganese, and a maximum of 0.2% each of titanium,nickel, tin and lead. Die-cast products such as automobile wheels castof this alloy have an overall combination of impact strength, fatiguestrength, tensile strength, yield strength and ductility characteristicswhich is superior to those of other aluminum base die-castingcompositions of which we are aware, including those characteristicsavailable in products die-cast from 364 alloy. Furthermore, thecorrosion resistance and machinability of wheels die-cast of thisalloy-are quite excellent andthe die-casting characteristics are as goodas any aluminum alloy available for the high stress applications forwhich the alloy of this invention is useful.

Although the advantages of this invention may beobtained within theaforementioned ranges, we have deter'mined that an especially usefulpreferred range of ingredients is a composition consisting essentiallyofaluminum, and by weight of the final composition 0.25

to 0.4% magnesium, 0.25 to 0.5% copper, 0.4 to 0.8% iron, 1 l to 12%silicon, 0.3 to 0.4% chromium, a maximum of 1% zinc, a maximum of 0.35%manganese, a maximum of 0.05% of each of titanium and nickel, and amaximum of 0.1% of each of tin and lead.

FIGS. 1 and 2 illustrate typical automobile wheels which have beendie-cast with aluminum base alloys.

Die-cast automobile wheels have been made from aluminum base alloys ofthis invention, as well as from a commercially available 364 alloy.Several such' wheels have been analyzed to determine their finalcomposition. Further, those wheels have been tested for yield strength,tensile strength and ductility.

Spoke wheels 10 die-cast generally in the configuration of- FIG. 1 wereanalyzed and were found to have the following compositions (theremainder being alu- A Alloy the f1rst time, for the subst1tut1on ofalummum base minum):

Mg Cu Fe Zn Si Mn Ti Ni Cr Sn Pb Be 364 Alloy .25 .07 .6I .04 8.63 .01.01 .01 .39 .02 .01 .0053

alloy automobile wheels for steel wheels on a much larger scale.

As its essential ingredients, the die-casting aluminum base alloy ofthisinvention comprises aluminum, and

Test bars were cut from those wheels and flange 12 test bars, spider 14test bars, and rim 16 test bars were tested for yield strength, fortensile strength, and for percent elongation with. the followingresults:

Offset equals 0.2 percent In these characteristics wheels die-cast froman alloy A of this invention were essentially equal to or substantiallybetter than those die-cast from 364 alloy,. and at a substantiallylesser overall cost. The machinability,

What is claimed is: l. A die-cast aluminum automobile wheel having aflange, spiders and a rim, said wheel consisting essentially ofaluminum, and by weight percentage of the the die-castingcharacteristics and the corrosion resis- 5 total composition, magnesium0.25 to 0.6%. copper. tance of the alloy A of this invention also wereall at 0.25 to 0.6%, iron 0.5 to 1.5%, silicon 11 to l3.5%, least asgood as, and in some instances substantially chromium 0.25 to0.4%,amaximum of 3% zinc,amaxbetter than those of the 364 alloy. imum of0.5% manganese and a maximum of 0.2% of Deep dish wheels 20 die-castgenerally in the configeach of titanium, nickel, tin and lead. urationillustrated in FIG. 2 were also tested for their 2; A di l in t bil h lhavi a yield Strength tensile Strength j P eloPgatlonflange, spiders anda rim, said wheel consisting essen- Tesi bars Cut m l 22, 24 and splders4 tially of aluminum and by weight percentage of the f l y? B fzlllmgWlthm the Preferred range offing total composition, magnesium 0.25 to0.4%, copper invention identified above and from a commercially 025 toiron 14 03% im 1 to 12% h avallable 3 alloy had the followmg Properties:15 mium 0.3 to 0.4%, a maximum of 1% zinc, a maximum Flange Spider Rim By 364 B 364 B 364 Yield Strength 22.000 16,800 23300 17.400 23,400l9.l00

(psil 18.300 l7.900 19,700 Tensile Strength 23.800 20,700 29,500 24,70025.400 20.000

(psi) 25.000 27,700 2 24.600 9i Elongation 2 2 /1 3 3% 3 2 Offset equals0.2 percent These last testsfr'om three die-cast wheels, two cast of0.35% manganese, a maximum of 0.05% of each of from alloys B of thisinvention and one cast from 364 titanium and nickel anda maximum of 0.1%of each of alloy even more graphically illustrate the substantially tinand lead. improved characteristics and properties of the alloys of. thisinvention as compared with those of the 364 alloy. =i

1. A DIE-CAST ALUMINUM AUTOMOBILE WHEEL HAVING A FLANGE; SPIDERS AND ARIM, SAID WHEEL CONSISTING ESSENTIALLY OF ALUMINUM, AND BY WEIGHTPERCENTAGE OF THE TOTAL COMPOSITION, MAGNESIUM 0.25 TO 0.6%, COPPER 0.25TO 0.6%, IRON 0.5 TO 1.5%, SILICON 11 TO 13.5%, CHROMIUM 0.25 TO 0.4%, AMAXIMUM OF 3% ZINC, A MAXIMUM OF 0.5% MANGANESE AND A MAXIMUM OF 0.2% OFEACH OF TITANIUM, NICKEL, TIN AND LEAD.
 2. A die-cast aluminumautomobile wheel having a flange, spiders and a rim, said wheelconsisting essentially of aluminum and by weight percentage of the totalcomposition, magnesium 0.25 to 0.4%, copper 0.25 to 0.5%, iron 0.4 to0.8%, silicon 11 to 12%, chromium 0.3 to 0.4%, a maximum of 1% zinc, amaximum of 0.35% manganese, a maximum of 0.05% of each of titanium andnickel and a maximum of 0.1% of each of tin and lead.